Seaming mechanisms for securing ends on can bodies



July 25, 1961 R- E- GEEsoN E L 2,993,457

SEAMING MECHANISMS FOR SECURING ENDS ON CAN BODIES Filed Feb. 18, 1359 3 Sheets-Sheet l Inventor: 4 l8 I9 20 /9 2O /8 T05671 E. eesow,

ArZJzur 13. 521407256)" July 25, 1961 GEESON Em 2,993,457

SEAHING MECHANISMS FOR SECURING ENDS 0N CAN BODIES Filed Feb. 18, 1959 4 3 Sheets-Sheet 3 1' nventors 1 0522? E. 66.2.90), ArZZz ugl. Jiuchbeyy.

United States Pat-euro 2,993,457 SEAMING MECHANISMS FOR SECURING ENDS N CAN BODIES Robert Ernest Geeson, Croydon, and Arthur Leslie Stuchbery, Enfield, England, assignors to The Metal Box Company Limited, London, England, a British company Filed Feb. 18, 1959, Ser. No. 794,145

- Claims priority, application Great Britain May 30, 1958 8 Claims. (Cl. 11324) This invention relates to seaming mechanism for securing ends on can-bodies and in particular to seaming 'mechanism of the kind in which a can body and the end to be seamed thereto are held stationary while a seaming roll or rolls is or are rotated about the can body.

When seaming ends to cans having a cross-section which is other than circular, for example cans the crosssection of which is substantially rectangular or oval, seaming mechanisms employed heretofore usually tend to cause the seaming rolls to run in towards the metal 'to be curled when approaching a corner and this movement is followed by an abrupt turn to the correct position thereof at the corner thus tending to cause the flanged metal being turned to form the seam to run towards the corner so that there is an excess of metal to be inturned at the corner. This disadvantage is due to a number of factors which differ to some extent according to the kind of devices used for tracking the seam- .ing rolls and for applying the seaming pressure but in principal it is due to the fact that with the mechanisms previously proposed it has not been found possible to ensure that the tracking rolls and seaming rolls are maintained in axial alignment throughout the seaming operations, always of course allowing for aberration when the seaming roll passes over the longitudinal seam formed in the can body.

It is a main object of the present invention to provide a seaming mechanism which reduces to a minimum the aforesaid disadvantage inherent in previously proposed mechanisms, which avoids the use of springs in the control of a seaming roll, which forms a tight seam while employing a seaming roll support the mass of mechanism can be used to seam ends to cans having a circular cross-section.

According to the present invention seaming mechanism for securing ends on can bodies comprises a chuck, a seaming roll support rotatable about the axis of the chuck, at least one freely rotatable seaming roll supported by one of a pair of arms secured to a hub which is rotatably mounted on a spindle which is fixedly mounted at its ends in the support to permit rocking movement of the armed hub and seaming roll about the spindle axis which is parallel with the axis of rotation of the support, a pair of frusto-conical cam followers spaced apart axially with their bases directed towards each other and supported by the other of said arms for rotation in opposite directions about an axis co-axial "ice with the axis of the seaming roll, and a pair of seaming cams having parallel faces each co-operating with one of said followers to effect movement of the seaming roll towards the chuck to perform a seaming operation and to cause the axis of the seaming roll to move in a path conforming to the peripheral contour of the chuck.

In order that the invention may be clearly understood one embodiment thereof will now be described, by way of example, with reference to the accompanying drawings, in which:

FIGURE 1 is a section through seaming mechanism according to the invention,

FIGURE 2 is a part of FIGURE 1 drawn to an enlarged scale, and

FIGURE 3 is an underneath plan of a part of FIG- URE 1 and illustrates diagrammatically the position of the chuck relative to the seaming rolls and their supporting arms.

Referring to the drawings, a chuck 1 is secured to a stem 2 and has a peripheral contour such as to fit into a can end, not shown, in the usual manner. The chuck is not rotatable but is supported for axial movement by a slidable bush 3. As viewed in FIGURE 1, the upper end of the chuck stem co-operates with a tubular extension 4, slidable axially in bushes 41, 42, having a chuck control cam 6 secured thereto by a draw bolt 5. Axial movement of the extension 4 is effected by rollers 7 co-operating with cam 6 and carried by a frame 8 provided with roller bearings 9 to rotate about a stationary spigot 10 by which the extension 4 is supported and guided for axial movement. The frame 8 is provided with gear teeth 11 and is driven by a pinion 12 rotation of which is elfected by the main drive, not shown, of the machine.

An ejector or knock-out rod 13 extends through the chuck, as is usual, and is movable axially relative to the chuck to disengage from the chuck a can end which has been seamed to a can body. Axial movement of the rod 13 is efiected by a cam 14 rotatable with the frame 8 and co-operating with rollers 15 carried by an arm 16 slidable in a grooved bracket 17.

In the preferred embodiment of the invention four equi-spaced seaming rolls 18, FIGURE 3, are provided and when, as illustrated in FIGURE 1, the first and second seaming operations are each to be performed while the can end and body remain in one position, each seaming roll is provided with a first operation peripheral seaming contour in the form of a groove 19, and with a second operation peripheral seaming contour in the form of a groove 20.

The seaming roll is mounted on a spindle 21, FIGURE 2, freely rotatable in an arm 22 which is secured to a hub 22a, said hub being rotatable for rocking movement on a stub shaft 23 which is fixedly mounted at its ends in a seaming roll support 24. The support 24 is rotatable about the axis of the chuck by a pinion 25, FIGURE 1, which is rotatable with the pinion 12 mentioned above. As the roll 18 is to perform both the first and the second seaming operations provision is made to accommodate the longitudinal side seams of can bodies during the second seaming operation. To this end the roll 18 is annular and is separated from the spindle 21 by a washer 26 which provides clearance permitting lateral movement of the roll 18 in a direction at right-angles to the axis of the spindle 21 when the roll 18 is passing over the body side seam. The roll 18 is normally retained in co-axial relation with the spindle 21 by balls 27 which are seated between the opposite sides of the seaming roll and plates 28 Which are co-axial with the spindle 21. As can be seen from FIGURE 2, the plates 28 are clamped between a shoulder 29 and a nut 38 on the spindle 21 so that they converge towards the spindle and are stressed so as to tend to urge the balls 27 into their seatings. When the seaming roll 18 is passing over a can body side scam the lateral movement of the roll rocks the balls partially out of their seatings and the stressed plates return the balls to the seatings as the roll passes the side seam thus causing the balls to return the roll 18 to the onrmal position thereof in which it is co-axial with the spindle 21.

The axis of the seaming roll 18 is caused to move in a path which conforms to the peripheral contour of the chuck by control cams 31, 32 and frusto-conical cam followers 33, 34 which, as can be seen from the drawings, are spaced apart axially with their bases directed towards each other. The followers 33, 34 are coaxial with the spindle 21 and are supported by a second arm 35 which is also secured to the hub 22a which is rotatably mounted on the fixed stub shaft 23 for rocking movement thereon. The relative axial positions of the cams 31, 32 is so chosen that the seaming roll 18 is preloaded to an extent slightly in excess of the load required thereon during seaming operations thereof and the contour of the cams corresponds to that of the chuck so that the axis of spindle 21 being co-axial with that of the spindle 36, on which the followers 33, 34 are freely rotatable, is constrained to move in a path which conforms to the peripheral contour of the chuck. The preloading of the followers 33, 34 eliminates vibration. The seaming pressure cannot displace the axis of spindle 21 relative to the axis of spindle 36 except by deflection of the arms which are rigidly constructed to reduce said deflection to a negligible degree.

During rotation of the support 24 the followers 33, 34 rotate in opposite directions about the spindle 36 thus avoiding undue wear. The location of the followers 33, 34 in the parallel side track formed by the sloping contoured faces of the cams 31, 32 eliminates vibration and provides a positive control of the arms 22, 35 without the use of springs.

The cams 31, 32 are each connected to a sleeve 37 which is slidable axially on the chuck stem 2 and is mounted at the lower ends, as viewed in FIGURE 1, of pillars 38. The pillars 38 are slidable axially in a stationary frame and to the upper ends of the pillars 38 there is connected a control cam 39 co-operating with rollers 40 carried by the rotating frame 8. As the frame 8 rotates the control cam 39 causes the cams 31, 32 to be lowered or raised respectively to apply or to relieve seaming pressure exerted by the seaming roll '18.

In operation, when the chuck has been located in a can end to be seamed to a can body the periphery of the chuck is aligned with groove 19 of the seaming roll 18. Rotation of frame 8 then causes cams 31, 32 to be lowered to apply the first operation seaming pressure to roll 18. The support 24 rotates for a predetermined number of revolutions for each rotation of frame 8 which rotates nly once for each can end fully seamed to a can body. Thus after a predetermined number of rotations of support 24 the cam 39 causes cams 31, 32 to be raised so as to disengage the rolls 18 from the seam being formed, and when this is done cam 6 causes the chuck to be lowered and aligned with the grooves 20 in rolls 18. Cam 39 then again applies seaming pressure to the rolls 18 so that they effect the second seaming operation. During this operation the rolls 18 may move laterally, as described above, as they pass over the side seam formed in the can body. After a further predetermined number of rotations of the support 24 during which the second seaming operation is completed, cam 39 again relieves the seaming stages and by different sets of seaming rolls, the apparatus above described is, in substance, duplicated and the can body after first operation seaming is transferred to the second operation apparatus. In a machine of this kind, however, only the second operation seaming rollers need be movable laterally relative to the spindles with which they are rotatable, it being understood with this form of machine the first operation rolls 18 are provided only with a groove 19, and the second operation rolls 18 are provided only with a groove 24 We claim:

1. Searning mechanism for securing ends on can bodies, comprising a chuck, a seaming roll support rotatable about the axis of the chuck, a freely rotatable seaming roll supported by one of a pair of arms secured to a hub which is rotatably mounted on a spindle which is fixedly mounted in the seaming roll support to allow a rocking movement of the armed hub and seaming roll about the spindle axis which is parallel with the axis of rotation of the seaming roll support, a pair of frusto-conical cam followers spaced apart axially with their bases directed towards each other and supported by the other of said arms for rotation in opposite directions about an axis co-axial with the axis of the seaming roll, and coaxial inner and outer seaming cams spaced apart axially of said chuck axis and having parallel faces each cooperating with one of said followers to effect movement of the seaming roll towards the chuck to perform a seaming operation and to cause the axis of the seaming roll to move in a path conforming to the peripheral contour of the chuck.

2. Seaming mechanism according to claim 1, wherein the seaming roll is provided with a first operation seaming profile and a second operation seaming profile spaced axially therefrom, the chuck is supported for axial movement into and out of alignment with said first and second operation profiles, and the seaming cams are supported for simultaneous axial movement to effect movement of the common axis of the followers and seaming roll towards and away from the axis of the chuck. w

3. Seaming mechanism according to claim 2, wherein axial movement of the seaming cams is effected by a control cam in a manner such that the first operation seaming pressure exerted by the seaming cams on the seaming roll is relieved during movement of the chuck from the first to the second seaming operation position thereof and pressure is re-applied preparatory to the second seaming op eration of the seaming roll.

4. Seaming mechanism according to claim 2, wherein the seaming roll is supported for lateral movement relative to its axis of rotation in a direction at right angles to the axis of rotation thereof and is movable in said direction on encountering the side seam of a can body during the second stage seaming operation thereby to ensure a substantially even seaming pressure around the perimeter of the can body. 7

5. Searning mechanism according to claim ,4, wherein the seaming roll is mounted on a spindle for rotation therewith and with a clearance permitting said lateral movement, and is normally retained in coaxial relation with the spindle by balls seated between the opposite sides of the seaming roll and plates coaxial with the spindle and stressed to urge the balls to the seated positions thereof.

6. Seaming mechanism according to claim 3, wherein the seaming roll is supported for lateral movement relative to its mis of rotation in a direction at right angles to the axis of rotation thereof and is movable in said direction on encountering the side seam of a can body during the second stage seaming operation thereby to ensure a substantially even seaming pressure around the perimeter of the can body.

7. Seaming mechanism according to claim 1 wherein said seaming cams and said followers are fI'UStOrCQDiCfil in outline.

8. Seaming mechanism according to claim 7 wherein 5 said seaming cams are tapered upwardly and said 01- 1,369,920 lowers are flared upwardly whereby a predetermined pre- 1,447,291 load may be applied to said cam followers. 2,907,293

References Cited in the file of this patent 5 UNITED STATES PATENTS 24 733 1,317,977 Johnson Oct. 7, 1919 25,274

6 Ennes Mar. "1, 1921 Arce Mar. 6, 1923 Peterson Oct. 6, 1959 FOREIGN PATENTS Norway June 29, 1914 Norway Dec. 21, 1914 

